September 2004
11-04-1010-00-000k
IEEE 802.11k
Wireless LANs
Proposal and Normative Text for a Scheduled Autonomous
Probe Response Generation Function
Date: September 9, 2004
Author:
Steve Emeott
[email protected]
Walter Johnson
[email protected]
Floyd Simpson
[email protected]
Stephen Wang
[email protected]
Tim Wilson
[email protected]
Motorola, Inc.
Abstract
This document contains normative text for the proposed addition of a Scheduled Autonomous Probe
Response (SAPR) generation function, which allows an AP to autonomously transmit Probe
Response frames at periodic intervals. The SAPR interval is indicated by a SAPR subfield included
in a SAPR information element within Beacon and Probe Response frames. The presence of
scheduled, autonomous Probe Response frames with the SAPR information element allows stations
to rapidly take measurements and find neighbor APs using passive scanning.
Submission
page 1
Motorola
September 2004
1
11-04-1010-00-000k
Normative Text for the Proposed Enhancements
7 Frame formats
7.2 Format of individual frame types
7.2.3 Management frames
7.2.3.1 Beacon frame format
Insert the following row at the appropriate location in Table 5 in 7.2.3.1 as shown:
Order
Information
Notes
TBD
Scheduled Autonomous
Probe Response
The Scheduled Autonomous Probe Response element shall be
present if
dot11ScheduledAutonomousProbeResponseFunctionEnabled is
true.
7.2.3.9 Probe Response frame format
Insert the following row at the appropriate location in Table 12 in 7.2.3.9 as shown:
Table 12 – Probe Response frame body
Order
Information
Notes
TBD
Scheduled Autonomous
Probe Response
The Scheduled Autonomous Probe Response element shall be
present
if
dot11ScheduledAutonomousProbeResponseFunctionEnabled is true.
7.3.2 Information elements
Insert the element IDs shown in the following table into Table 20 replacing previously reserved values:
Information Element
Element ID
Scheduled Autonomous Probe Response
TBD
Insert the following subclauses with the figures included therein, after subclause 7.3.2.27:
7.3.2.28 Scheduled Autonomous Probe Response information element
The Scheduled Autonomous Probe Response information element contains a Scheduled Autonomous Probe
Response Inverval field as shown in Figure kXX.
Octets:
Element ID
Length
Scheduled
Autonomous Probe
Response Interval
1
1
2
Figure kXX—Scheduled Autonomous Probe Response information element format
The Length field shall be set to 2.
Submission
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Motorola
September 2004
11-04-1010-00-000k
The Scheduled Autonomous Probe Response Interval field shall contain the number of time units (TU)
between two consecutive scheduled, autonmous Probe Response frame transmissions. The Scheduled
Autonomous Probe Response interval shall be smaller than regular beacon intervals.
11 MAC sublayer management entities
Insert the following subclauses with the figures included therein, after subclause 11.8:
11.9 Usage of Scheduled Autonomous Probe Response element
The presence of the Scheduled Autonomous Probe Response (SAPR) information element in a Probe
Response or Beacon frame indicates that an AP supports an autonomous probe response generation
function and generates Probe Response frames at the interval specified in the element.
APs supporting the Scheduled Autonomous Probe Response (SAPR) generation function shall
automatically generate Probe Response frames including the SAPR information element at the interval
specified by the Scheduled Autonomous Probe Response Interval field, as illustrated in Figure kZZ. The
SAPR generation function shall transmit the Probe Response frame including the SAPR information
element when the value of the TSF Timer modulo the SAPR interval (converted to microseconds) equals 0.
The Probe Response frame generated by the SAPR generation function shall be addressed to the broadcast
destination address.
Beacon
Beacon
SAPR SAPR
SAPR Interval
Beacon Interval
Figure kZZ - Scheduled Autonomous Probe Response generation (informative)
Annex A – PICS
A.4 PICS proforma–IEEE Std 802.11, 1999 Edition9
A.4.3 IUT configuration
Append this entry to the end of this table:
Item
*CF11
IUT configuration
Is Scheduled Autonomous Probe
Responses implemented?
References
Status
Support
7.2.3.1, 7.3.2.9,
7.3.2.28, 11.9
O
Yes, No
References
Status
Support
A.4.4.1 MAC protocol capabilities
Insert this new item after PC11.10 in A.4.4.1:
Item
PC11.11
Submission
Protocol Capability
Scheduled Autonomous Probe
Response Function
11.9
page 3
CF11:M
Yes, No. N/A
Motorola
September 2004
11-04-1010-00-000k
Annex D
In the dot11StationConfig table of Annex
“dot11RadioMeasurementEnabled” entry:
D,
insert
the
following
dot11ScheduledAutonomousProbeResponseFunctionCapable
dot11ScheduledAutonomousProbeResponseFunctionEnabled
dot11ScheduledAutonomousProbeResponseInterval
entries
after
the
TruthValue,
TruthValue,
INTEGER,
Insert the following elements to the dot11StationConfigTable element definitions after
dot11RadioMeasurementEnabled and renumber dot11RadioMeasuremtnProbeDelay to 42:
dot11ScheduledAutonomousProbeResponseFunctionCapable OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This attribute, when TRUE, indicates that the AP is capable
of supporting the Scheduled Autonomous Probe Response
Generation Function. The capability is disabled otherwise.
The default value of this attribute is FALSE."
::= { dot11StationConfigEntry 39 }
dot11ScheduledAutonomousProbeResponseFunctionEnabled OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"An AP may use the defined Scheduled Autonomous Probe
Response Generation Function procedures if this attribute is
TRUE. The default value of this attribute is FALSE."
::= { dot11StationConfigEntry 40 }
dot11ScheduledAutonomousProbeResponseInterval OBJECT-TYPE
SYNTAX INTEGER (1..65535)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This attribute shall specify the number of TUs that an AP
shall use for scheduling scheduled, autonomous Probe Response
transmissions. The value is transmitted in Beacon and Probe
Response frames if enabled.”
::= { dot11StationConfigEntry 41 }
Submission
page 4
Motorola